Air-conditioner of construction machinery

ABSTRACT

The invention provides an air-conditioning apparatus that maximizes the space in an operator&#39;s cab and provides a comfortable working environment for the operator of a construction machine. The body unit of the air-conditioning apparatus is disposed under the floor surface of the cab, cold air and hot air ducts are connected to the body unit, and routed under the floor of the cab to be passed through the floor surface and taken out into the inside of the cab using cold air and hot air outlets disposed at both left and right sides at the front part of the cab. Also, by providing two evaporators, air of different temperatures can be blown through the left and right outlets.

BACKGROUND OF THE INVENTION

1. Field of Invention

The invention belongs to the technical field of an air-conditioningapparatus to be incorporated in a construction machine, such as ahydraulic excavators, etc.

2. Description of Related Art

Recently, an air-conditioning apparatus has become a widely acceptedaccessory in the operator's cab of a construction machine, such as ahydraulic excavator, etc., in order to improve the operator's workingenvironment. Conventionally, a body unit incorporates a heat exchangerfor cold air, a heat exchanger for hot air and a blower, etc., andcomprises an air-conditioning apparatus has been disposed below orbehind a seat in an operator's cab. A duct that becomes an outlet forthe air-conditioned air produced by the body unit is pipe-arranged, forexample, toward the right side or rear side within the operator's cab.However, the body unit and ducts occupy a considerable portion of thespace within the operator's cab.

Disposed in the operator's cab are various members and devices, such asa console box in which control levers, etc. are provided, operationpedals, a monitoring device, etc., a seat on which an operator sits, andthe above-described air-conditioning apparatus. Therefore, Applicantshave identified a need for effectively using the space in an operator'scab by saving the space taken by an air-conditioning apparatus, whereinthe invention solves the problems.

Furthermore, it is common that, in a construction machine, an entrancedoor is provided at the left side of the operator's cab. Therefore, itis difficult to dispose a duct for the above-described air-conditioningapparatus at the left side of the operator's cab in such a machine.Accordingly, there is the case where there is no outlet in the door toprovide a defrosting outlet.

In addition, where one side of the operator is exposed to sunlight, itis more comfortable for the operator if the temperatures of the cold airblown from the left and right ducts are different, wherein thetemperature at the side which is exposed to sunlight is made slightlylower, or cooler, while the temperature at the opposite side is madeslightly higher, or warmer. However, the prior art devices have aproblem in that the temperature of the cold air simultaneously blownfrom the left and right ducts cannot be made different from one another.This point is also an object of the invention.

SUMMARY OF THE INVENTION

The invention addresses the above-described problems. In the invention,a body unit of an air-conditioning apparatus, into which heat exchangersfor cold air and hot air are incorporated, is provided under the floorof a cab and ducts, which become outlets of air-conditioned air producedby the body unit, arc routed under the floor of a cab and are taken outinto the inside of the operator's cab.

With such a structure, it is not necessary to secure space for disposingthe body unit of an air-conditioning apparatus and ducts thereof in theoperator's cab. As a result, the space in the operator's cab can beeffectively utilized, and at the same time the degree of freedom in thelayout for disposing the ducts can be increased as potential advantagesachieved by the invention.

In the invention, an opening is provided on the floor surface of theoperator's cab, and a part of the body unit disposed under the floor ofthe operator's cab protrudes into the operator's cab through theopening, whereby the portion protruding into the operator's cab can beprotected.

Furthermore, in the invention outlets of cold air and/or hot air ductsare disposed at both the left and right sides at the front part of theoperator's cab, whereby the temperature around an operator can beuniformly maintained in a stabilized state, and a comfortable workenvironment can be provided. In addition, because an outlet for hot air,which functions for defrosting, is provided at both left and rightsides, defrosting performance of not only the front window of theoperator's cab but also the left and right windows thereof can befurther improved.

In the invention, first and second cold air heat exchangers areincorporated into the body unit, cold air from the respective cold airheat exchangers is separately mixed with hot air from a hot air heatexchanger, and air of different temperatures is blown from the left andright outlets, whereby the working environment of the operator can bemade even more comfortable.

Thus, the invention is useful and effective in cases where, when anair-conditioning apparatus is disposed in civil engineering and/orconstruction machinery, such as hydraulic excavators, etc., the space inan operator's cab can be effectively utilized, the temperaturesurrounding an operator can be evenly maintained in a stabilized state,and the working environment of the operator can be made comfortable.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the drawings, inwhich:

FIG. 1 is a plan view showing a simplified inside of a cab;

FIG. 2 is a side elevational view showing the simplified inside of thecab;

FIG. 3 is a front elevational view showing the cab with a part thereofomitted;

FIG. 4 is a plan view showing a body unit;

FIG. 5 is a side elevational view showing the body unit; and

FIG. 6 is a front elevational view showing the body unit.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

In the drawings, reference number 1 denotes a cab (corresponding to theoperator's cabin of the invention) of a construction machine, such as ahydraulic excavator, etc. A front window 1 a is provided at the frontpart of the cab 1, a right window 1 b is provided at the right side partthereof, and a left door 1 c is provided at the left side part thereof,respectively. Furthermore, various members and devices, such as a seat 2on which an operator sits, left and right operation pedals 3L, 3R, aconsole box (not illustrated) equipped with control levers, a monitoringdevice, a controller, etc., are disposed in the cab 1.

On the other hand, reference number 4 (FIG. 4) denotes a body unit of anair-conditioning apparatus. The body unit 4 comprises a box-shaped thintype casing body 5 in which a pair of left and right evaporators 6L,6R(corresponding to a heat exchanger for cold air conditioning to theinvention), a beater core 7 (corresponding to a heat exchanger for hotair according to the invention), etc., are incorporated. A blower unit 8is further incorporated in the rear portion of the casing body 5 andmade integral therewith. The body unit 4 is attached on the underside ofthe floor plate 9 of the cab 1 in a state where the casing body 5 ispositioned below the seat 2 and the blower unit 8 is positionedessentially behind and below the seat. A motor 8 a, that powers theblower unit 8, protrudes from an opening 9 a provided on the floor plate9 to the inside of the cab 1. Accordingly, the motor 8 a is accommodatedin the cab 1, whereas the body unit 4 is accommodated below the floor.Thus, the motor 8 a can be protected from muddy water, etc.

Furthermore, left and right connection ports 5 a, 5 b for cold air, towhich the base portions of left and right cold air ducts 10L, 10R areconnected, are formed at the front part of the left and right sides ofthe casing body 5, and left and right connection ports 5 c, 5 d for hotair, to which the base portions of left and right hot air ducts 11L, 11Rare connected, are formed at the front side of the casing body 5.Connection port dampers 12 a, 12 b, 12 c, 12 d, the opening degree ofwhich is adjustable, are provided at the respective connection ports 5a, 5 b, 5 c, 5 d, so that the blowing amount from the respectiveconnection ports 5 a, 5 b, 5 c, 5 d to the ducts 10L, 10R, 11L, 11R canbe adjusted.

The above-described left and right cold air ducts 10L, 10R are routedbelow the floor plate 9 of the cab 1 from the left and right cold airconnection ports 5 a, 5 b to the left and right sides of the cab 1. Theyextend forward, and are taken out to the inside of the cab 1 from thesurface of the floor plate 9 to the outside of the left and rightoperation pedals 3L, 3R. Thus, the ducts 10L, 10R are disposed so as toreach the left and right side parts of the cab 1. In addition, the coldair outlets 10La, 10Ra are connected to the tip end portions of theducts 10L, 10R. The cold air ducts 10L, 10R are devised so that aircooled by the left and right evaporators 6L, 6R blows from the cold airoutlets 10La, 10Ra toward the upper body of an operator.

Furthermore, the left and right hot air ducts 11L, 11R are routed belowthe floor of the cab 1 from the left and right hot air connection ports5 c, 5 d toward the front part of the cab 1 and taken out from theforward surface of the floor plate 9 forward of the left and rightoperation pedals 3L, 3R to the inside of the cab 1. After that, theducts 11L, 11R are routed so as to extend outward in the left and rightdirections along the front side part of the cab 1. The hot air outlets11La, 11Ra are connected to the tip end portions thereof. The hot airducts 11L, 11R are constructed so that air heated by the heater core 7is blown from the hot outlets 11La, 11Ra toward an operator's feet, thefront window 1 a, right side window 1 b and door 1 c. Accordingly, theducts 11L, 11R function for both heating and defrosting.

On the other hand, left and right guide dampers 13L, 13R are rotatablysupported on the casing body 5. They can be displaced to a heatingposition (shown by a dotted line in FIG. 4) where air sent from theblower unit 8, and passed through the respective left and rightevaporators 6L, 6R, is caused to flow into the heater core 7, a coolingposition (shown by a one-dashed chain line in FIG. 4) where streams ofair from the respective left and right evaporators 6L, 6R are preventedfrom flowing to the heater core 7, and a mixing position (shown by atwo-dashed chain line in FIG. 4; the streams of air at the mixingposition being illustrated by the arrows in FIG. 4) which is located atan intermediate position between the cooling position and heatingposition and permits a part of the air coming from the respective leftand right evaporators 6L, 6R to flow into the heater core 7. Further,the guide dampers 13L, 13R are controlled so that they are positioned atthe cooling position when cooling is carried out, and at the heatingposition when heating is carried out, and are controlled so that theyare positioned at the mixing position when performing bi-level control.Therefore, in the bi-level control, cold air whose coldness is temperedis blown from the cold air outlets 10La, 10Ra, and hot air whose warmthis tempered is blown from the hot air outlets 11La, 11Ra. Furthermore,in the bi-level control, the left and right guide dampers 13L, 13R arestructured so that the rotating positions thereof can be separatelycontrolled, whereby it becomes possible to alter the mixing ratio ofcold and hot air, which are mixed via the respective left and rightguide dampers 13L, 13R. Moreover, by controlling the opening degree ofthe above-described connection dampers 12 a, 12 b, 12 c, 12 d, thetemperature and amount of air blown from the left and right cold air andhot air outlets 10La, 10Ra, 11La, 11Ra can be set so that they aredifferent at the left and right sides.

In such a structure as described above, the body unit 4 of theair-conditioning apparatus is accommodated below the floor surface 9 ofthe cab 1, and at the same time, the left and right cold air and hot airducts 10L, 10R, 11L, 11R, which are connected to the body unit 4 androuted below the floor of the cab 1, reach the front part of the cab 1.Furthermore, the ducts are taken from the front part of the cab 1 intothe inside thereof, and are connected to the cold air and hot airoutlets 10La, 10Ra, 11La, 11Ra, which are disposed at both left andright forward sides in the cab 1.

As a result, it is not necessary to provide a space for disposing thebody unit 4 of the air-conditioning apparatus and ducts 10L, 10R, 11L,11R within the cab 1. Therefore the space for disposing other membersand devices and an operating space of an operator can be increased, andthe space in the cab 1 can be effectively utilized.

Furthermore, because the ducts 10L, 10R, 11L, 11R are routed below thefloor of the cab 1, the degree of freedom for the piping layout can beincreased as it is possible to easily route pipes at the left side ofthe cab 1, the side at which the door 1 c is installed. Accordingly,because the hot air outlets 11La, 11Ra which function for defrostingboth left and right sides of the cab 1 can be provided, the defrostingperformance with respect to the door 1 c can be further improved. Also,because the cold air outlets 10La, 10Ra are disposed at the left andright sides of the cab 1, it is possible to evenly maintain thetemperature surrounding an operator in a stabilized state, and acomfortable working environment can be brought about.

Furthermore, in such a structure, the motor portion 8 a of the blowerunit 8, that is part of the body unit 4, protrudes from the opening 9 aopened in the floor plate 9 of the cab 1 into the inside of the cab 1and is accommodated in the cab 1. As described above, because the motorportion 8 a is accommodated in the cab 1, through the opening 9 a in thefloor plate 9, the motor portion 8 a can be protected from impacts fromcontact with muddy water or pebbles, etc., although the bulk of the bodyunit 4 is accommodated below the floor of the cab 1. In addition,portions that are caused to protrude into the cab 1 are not limited tothe motor portion 8 a. Any portions for which protection is necessarycan be accommodated in the cab 1.

Also, a pair of left and right evaporators 6L, 6R are provided in thebody unit 4. Thus, air cooled by the separate left and right evaporators6L, 6R may be separately mixed with air heated by the heater core 7 inthe bi-level control. As a result, for example, in the case where theupper part of an operator's body is exposed to sunlight, the blowingtemperature from the left and right outlets 10La, 10Ra, 11La, 11Ra canbe separately set so that the temperature at the side exposed tosunlight is made slightly lower and the temperature at the side opposedthereto, i.e., shaded, is made slightly higher, wherein the workingenvironment of an operator can be made even more comfortable.

1. An air-conditioning apparatus for a construction machine, comprising:a body unit of the air-conditioning apparatus; heat exchangers for coldair and hot air incorporated in the body unit, the body unit mountedunder the floor of an operator's cab; ducts which become outlets ofair-conditioned air produced by the body unit are routed under the floorof the operator's cab and are passed through the floor into the insideof the operator's cab; and an opening is provided in the floor surfaceof the operator's cab, with a part of the body unit protruding into theoperator's cab through the opening.
 2. The air-conditioning apparatus asset forth in claim 1, wherein the outlets of cold air and/or hot airducts are disposed at both left and right sides at the front part of theoperator's cab.
 3. The air-conditioning apparatus as set forth in claim2, wherein, although first and second cold air heat exchangers areincorporated into the body unit, cold air from the respective cold airheat exchangers is separately mixed with hot air from a hot air heatexchanger, whereby air of different temperatures is blown out from leftand right outlets.
 4. A vehicle, comprising: an operator cab with afloor plate; and an air conditioning unit beneath the floor plate andmounted to a lower surface of the floor plate, the air conditioning unitcomprising: a blower unit; a motor powering the blower unit; a bodyunit; and a duct system extending from the body unit beneath the floorplate substantially along both sides of the operator cab and openinginto the operator cab at a front thereof, wherein the floor plate of theoperator cab has an opening that receives the motor such that the motoris housed within the operator cabin.
 5. The vehicle according to claim4, wherein the body unit has therein: a pair of evaporators; a heaterelement; and a guide damper associated with each evaporator to directair flow emerging from the associated evaporator.
 6. The vehicleaccording to claim 4, wherein the duct system comprises: a cold air ductextending from an associated evaporator along a respective side of theoperator cabin; a hot air duct extending from the body unit toward afront of the operator cabin along each side of and substantiallyparallel to a center line or longitudinal axis of the operator cabin;and a hot air exhaust duct and a cold air exhaust duct extending intothe operator cabin at respective front corners of the operator cabin,wherein the floor plate has duct openings to allow the cold air ductsand hot air ducts to connect with the respective cold air exhaust ductsand hot air exhaust ducts.
 7. The vehicle according to claim 5 whereinthe duct system comprises: a cold air duct extending from an associatedevaporator along a respective side of the operator cabin; a hot air ductextending from the body unit toward a front of the operator cabin alongeach side of and substantially parallel to a center line or longitudinalaxis of the operator cabin; and a hot air exhaust duct and a cold airexhaust duct extending into the operator cabin at respective frontcorners of the operator cabin, wherein the floor plate has duct openingsto allow the cold air ducts and hot air ducts to connect with therespective cold air exhaust ducts and hot air exhaust ducts.
 8. Thevehicle according to claim 4, wherein the body unit further comprises adamper at each duct of the duct system extending from the body unit. 9.The vehicle according to claim 5, wherein the body unit furthercomprises a damper at each duct of the duct system extending from thebody unit.
 10. The vehicle according to claim 7, wherein the body unitfurther comprises a damper at each duct of the duct system extendingfrom the body unit.
 11. The vehicle according to claim 8, furthercomprising a controller that controls the opening of each damper. 12.The vehicle according to claim 9, further comprising a controller thatcontrols the opening of each damper.
 13. The vehicle according to claim10, further comprising a controller that controls the opening of eachdamper.
 14. An air-conditioner used in a vehicle having a floor plate,the air-conditioner unit comprising: a blower unit; a motor powering theblower unit; a body unit; and a duct system extending from the body unitbeneath the floor plate substantially along both sides of the operatorcab and opening into the operator cab at a front thereof, wherein thefloor plate of the operator cab has an opening that receives the motorsuch that the motor is housed within the operator cabin.
 15. The vehicleaccording to claim 14, wherein the body unit has therein: a pair ofevaporators; a heater element; and a guide damper associated with eachevaporator to direct air flow emerging from the associated evaporator.16. The air-conditioner according to claim 15, wherein the duct systemcomprises: a cold air duct extending from an associated evaporator alonga respective side of the operator cabin; a hot air duct extending fromthe body unit toward a front of the operator cabin along each side ofand substantially parallel to a center line or longitudinal axis of theoperator cabin; and a hot air exhaust duct and a cold air exhaust ductextending into the operator cabin at respective front corners of theoperator cabin, wherein the floor plate has duct openings to allow thecold air ducts and hot air ducts to connect with the respective cold airexhaust ducts and hot air exhaust ducts.
 17. The air-conditioneraccording to claim 16, wherein the body unit further comprises a damperat each duct of the duct system extending from the body unit.
 18. Theair-conditioner according to claim 17, further comprising a controllerthat controls the opening of each damper.